Safety battery connector switch



y 1953 GQG. TRUAX 2,639,341

SAFETY BATTERY CONNECTOR SWITCH Filed April 27, 1948 INVEN TOR.

George TruQX Y AT TORNE YS Patented May 19, 1953 UNITED" STATES" PATENT SAFETY BATTERY- CONNECTOR swrrcn' i 7 George G. T ruax, Renton, Pa. Application April 27, 1948, Serial No. 23,501

an explosive detonator, or an equivalent device. 1

In electrically discharging explosives, a number of accidents have been caused by premature explosions caused by'some :part of the firingcircuit, and particularly the contacts of the battery connector, coming into contact with a live wire or other source of electrical energy while the charge is being prepared and the firing wires connected thereto. Various regulations have been promulgated to overcome this situation, one such regulation requiring that the contacts of the connector be electrically connected together, or short-circuited, until the proper time for firing the charge.

With present-day equipment this is not always easy to accomplish and is frequently forgotten with the result that an unnecessarily large number of premature explosions still occur in mining and quarrying operations.

It is among the objects of the present invention to provide an improved safety connector so constructed and arranged that the contact points thereof are automatically retractedinto a casing of electrically .insulating material and are electrically inter-connected or short-circuited when theconnector is not in use, thereby substantially eliminating any danger of premature explosions in the use of the connector for firing explosive charges, which connector is also effective to avoid injury to a person using it by arcing or sparking of the current at the contact points, and which connector is automatically made safe when not in use, is light in weight, easy to handle, and simple, durable and economical in construction.

Other objects and advantages will become apparent from a consideration of the following description and appended claims in conjunction with the accompanying drawing, wherein:

Figure 1 is a top plan view of a battery connector, illustrative of the invention;

Figure 2 is a view similar to Figure 1 with the top cover of the connector casing removed;

Figure 3 is a longitudinal cross-section of a fragmentary portion of the connector and is taken substantially in the plane of the section line 3-3 of Figure 1; and

Figure 4 is a transverse cross-section taken substantially in the plane of the section line 4--4 of Figure 1.

With continued reference to the drawing, the

3 Claims. (01. 200-51) improved battery connector comprises a hollow, paddle-shaped casing, generally indicated at H), having a substantially cylindrical handle portion H and a hollow receptacle portion l2. This casing preferably comprises a body portion [3, illustrated in Figure 2, having a'groove I4 extending longitudinally through the handle portion and a generally triangular concavity IS in the recep tacle portion I2 thereof with an apex of the triangular concavity atthe adjacent end' of the handle portion II, and a cover plate I6 overlying and secured to the open face of the body por-- tion 13.

A .V -shaped strap I! of electrically conductive metal is secured to the inner sidewalls of the body portion" l3 by suitable means, such as the screws [8, and is provided at its apex with an opening l9.

A triangular block 20 of electrically insulating material is slidably mountedin the interior of the receptacle portion of the, casing and a pair of straps 2| of electrically conductive metal is secured to the divergent sides. of this block in position such that they are substantially parallel to the legs of the v-shaped strap H. The straps 2| are separated at their adjacent ends, as indicated at 22, and are extended at their outer ends beyond the corresponding end of block 20 to providerespective contact;points 23 extending beyond the block 20. Anend wall 24 is se cured in theopen-end of the receptacle portion of the casing andis spaced at its ends from the correspondingside walls of the body portion l3 to provide passageways 25 in which the contact points are slidably received.

A coiled compression spring 26 is disposed between the end'wall 24 and the block 20 being seated in a recess 21 provided in the block, which spring acts to resiliently force the block 20 inwardly of the receptacle portion of the casing until the block-carried straps 2i are in electrically conductive contact with the V-shaped strap l1 and the contact points 23 are retracted into the hollow casing, as clearly illustrated in Figure 2. When the block 20 is in the illustrated position the block-carried straps 2| are electrically inter-connected or short-circuited by the V-shaped strap l1 and the connector is thereby rendered inoperative to conduct current to an explosive detonator.

The side wall I6 of the casing is provided with an elongated opening 28 adjacent the inner end of the handle portion II and a thumb button 28 is secured to the block 20 by suitable means. such as the screws 30, and extends through the A guard spring 32 is seatedinai rebessdlpro vided in the outer end of the handle a-nd bears at its outer end against a button 34 apertures for the passage of the conductors} or wirest i in therethrough, the wires being knotted together v at the outer side of the button. This guardspring and button provide a protective guard for the portions of the'conduc-tors extending-putof the handle portion of the connectorcasing Thecover plate 1.6 is detachably secured to the body portion 13' by suitable meanspsuch as the screws 35,- and the width-of the: receptacle pore tion 12 is such thatthe contact 23 are spaced" apart a' distance" substantially equal to the distance between a pair of conventional battery poles. v V The invention be embodiedinother specific' forms unmoutdepartingfrom thespirit or essential-- characteristics thereof. The present embodiment is, therefore, to be considered in all respects as-yillustrative and not restrictive, the scop'eoi the invention being indicated-by the ap= pended claims rather'thanby the foregoing description,:- and all changes which come withinthe meaning and range of equivalency of the claims are; therefore; toPbEembraCedtherein:

What is claiml-idisiz v 1'. An electrical connectorcomprising: a hollow casing of electrically insulating material'includ mg a handle portion and .a receptacle portion; said receptacle portion having a generally triam giilar interior withan apexat the adjacent end of saidh'andle portion andan elongated opening therein adj acent said handleportionra strap'of electrically conductive matenars c ed to the interim-wallet said receptacle-portionhaving an opening in the apex portion ther'or, a triangmar block of' e1eetrrcallyinsuiating mate-- rial in said receptacleporti-on slidable' toward and away from said v sh aped strap, a sneer-straps secured te-said-bloc he mean divergent-side thereof, and eac h vidinga co nta/c't pointertending outwardly pf the side 'o said-blo'okreniote' from said handle 'portloh; extefiams' I oints when in retrac tedpositioii;

across the open end of and spaced at its ends from the side walls of said receptacle portion to provide respective passageways for said contact points, a compression spring between said end wall and said block resiliently urging said block inwardly of said casing until said contact points are retracted into said casing and said blockcarried straps are in electrical contact with said V-shaped strap,a thumb button. secured to said block and extending through the elongated opening in said casing for moving said block to separate said block-carried straps from said V-shaped strap and project said contact points out of said.

casing..anda of electrical conductors extending through said handle portion and the openingirrsaid V-shaped strap and electrically connectedtpflineyto each of said block-carried straps,

1 electrical connector comprising a hollow casing of insulating material having a handle portion and an elongated opening therein adjacent said handle" portion; a block of insulating material movable insaid' casing, a pair of con tact pointscarried-by said block retractible into anii'extendible out of said casing'uponmovement of saidblock; a; spring in said casing operative to move said block in-a point-retractmg siren tio'n, a thumb button secured to said block and extending tliro'ng'nthe opemng in said casing-to move said block in a point projecting' direction; pair of conductors extending through said lian die and electric-ally connectedone toeach of said contact points and means in s-aideasmg operato short circuit said- Contact points wheii in retracted position. I

3*. electrical connectorccmprismg e-nouaw casing having a handle portion and an elongated opening through the wall thereof adjacent said handle portion; a blockor insulating material movable in said casing-a pair of spaced-apart contact points carried by said block extendible out of'the e'rido'f said'casing-iopposite salesman and retractible into said asinggs nng' m-eans in said casingopera-tive 'to'r'nove said block in a palat l-ma ting direction; a; thumb" button se cured toqs'aidb1ock and p ictins' hrough the openingiii said casing to more said blocliin a point e'xtending' direction" against the force" of 'sa-id'sfpi ing' means, apaancf eleotrical conductors 'ei'ztending' thrl'iug'h saidhandle electrical-l? tonne-mes ns to each of said contentment and means in said casing adjacent said block tive to electrically inter said contact seems G.

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